For a typical U.S. home, heating and air conditioning account for about 44% of the energy use. Heating is the largest energy expense in most homes, accounting for almost two-thirds of annual energy bills in colder areas of the country. Heating systems in the United States emit one billion tons of carbon dioxide (CO2) and about 12% of the sulfur dioxide and nitrogen oxides emitted by the nation.

The American Council for an Energy-Efficient Economy (ACEEE) estimates that the incremental cost of an air conditioning unit with a SEER rating of 13 relative to today's minimum standard SEER 10 unit will be about $171. With typical household savings of $48 per year based on current national average electricity prices, the higher standard pays for itself in about 3.5 years. Central air conditioners last about 18 years.

The average home could reduce their heating and cooling bills by as much as 40% by replacing old equipment with the ENERGY STAR labeled equivalent.

More than 40% of existing homes and 75% of new homes have central air conditioning. A properly sized and installed central air conditioner uses 20% less electricity than a standard new central air conditioner. Studies show that one-third to one-half of home air conditioners don't work the way they should because they are oversized (and thus, inefficient). Increasing the efficiency of central air-conditioning units installed and properly sizing the equipment can dramatically reduce energy consumption, related pollution, and utility bills.

Cooling energy use is second only to lighting energy use in commercial buildings. In California, cooling commercial buildings accounts for 14% of peak electrical demand.

Geothermal heat pumps are among the most efficient and comfortable heating and cooling technologies currently available. Geothermal heat pumps take advantage of stable temperature conditions in the ground and the nearly limitless supply of renewable heating and cooling energy that is stored there. In addition to producing radically lower heating bills, Energy Star labeled geothermal heat pumps are generally quieter than conventional systems, and they include water heating capabilities.

Desiccant cooling and dehumidification systems operate without the use of ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). They can efficiently handle the larger flow rates of outside air required by new indoor air quality standards.

Desiccant dehumidification could reduce total residential electricity demand by as much as 25% in humid regions.